Freewheeling stoker fan



Nov. 28, 1950 E. c. WEBB 2,531,796

FREEWI-IEELING STOKER FAN BMW/W Patented Nov. 28, 1950 FREEWHEELING STOKER FAN Ernest C. Webb, Bay Village, Ohio, assignor to Iron Fireman Manufacturing Company, Portland, Oreg.

Application January 3, 1945, Serial No. 571,180

(Cl. fill-72) 5 Claims.

This invention relates generally to stokers for solid fuel and particularly to a free wheeling stoker fan.

The main object of this invention is to provide a fan adapted to reduce off period smoking.

The second object is to produce a means for continuing the supply of air to a stoker or other fuel burning device for a period of time after the power supplied to the motor driving the air supply fan has been shut off.

The third object is to produce a fan of the class described in which the greatest supply of air is furnished at the shut-down period, after which a gradually diminishing supply is furnished.

I accomplish these and other objects in a manner set forth in the following specification as illustrated in the accompanying drawing, in which:

Fig. 1 is an end elevation of a stoker motor and a fan driven thereby.

Fig. 2 is a horizontal section through the coal hopper to disclose the coal worm in the bottom thereof.

Fig. 3 is a vertical section taken along the line 3-3 in Fig. 2.

Fig. 4 is a section taken along the line 4-4 in Fig. 3.

Similar numerals refer to similar parts throughout the several views.

Referring in detail to the drawing, there is shown a retort H] of a stoker. To this retort coal or other solid fuel is carried through a coal tube l l communicating with a hopper 12 by means of a coal feeding worm l3, driven from r a transmission I4 by means of the motor 45, whose pulley I6 is connected by means of a belt IT to the pulley 18 of the shaft H], from which power flows to the transmission M through the gearing (not shown).

The shaft I9 is enclosed within a housing 2! which is integral with the motor supporting casting 2|. The housing 2!] is provided with a flange 22, to which is attached the fan guard 23. On the outer end 24 of the housing 2!! is mounted an anti-friction bearing 25, which supports the streamlined fan hub 26. A cover plate 21 is mounted on the hub 26 and is used to keep foreign substances out of the hearing and insure the positioning of the parts. The hub 26 is provided with a cylindrical bore 28, in which is disposed an overrunning clutch element 29, which is keyed to the shaft portion 30 by means of the key 3|. The element 29 is provided with wedge shaped recesses 32, in each of which is placed a ill roller 33 which is free to rotate in one direction but will lock in the opposite direction.

The shaft I53 has its outer end 3 1 reduced to receive the anti-frictionbearing 35, which supports the outer end of the member 26. Mounted on thehub 25 is a'fan 36. The blades -31 of the fan 36 are supported at one end by the fly wheel 38. A ring guard as is provided around the exterior of the fan 36.

The operation of the device is as follows. Assuming that the stoker is being operated by the motor l5, that is, fuel is being delivered by means of the screw i3 and air is being delivered by means of the fan 36 under the driving action of the motor l5. With the present apparatus, if the motor i5 is stopped for any reason whatsoever, then the free wheeling action of the member 29 permits the fly wheel 38 to continue in its movement without being retarded by the motor I5, and this continuing movement driving the fan 36 and supplying the necessary air to the combustion made possible by the volatiles driven off by the heat previously generated, that is, during the period of operation when a supply of air is especially needed, the fan, due to the inertia of its fly wheel 38, continues to supply a driving force to the fan after the worm [3 has ceased supplying fuel to the combustion, thereby bringing about a highly desirable condition in the combustion chamber.

While I have thus illustrated and described my invention, it is not my desire to be limited to the precise form shown herein, and I intend to cover such forms and modifications of the invention as fall fairly within the appended claims.

I claim.

1. In a fuel burner, the combination of a fuel conveyor, an air conveyor operatively associated therewith, said air conveyor comprising an impeller shaft and an impeller, a motor operatively connected with said fuel conveyor and said impeller shaft, and free wheeling means interposed between said impeller and said shaft whereby said air conveyor is adapted to operate after an operation by said fuel conveyor.

2. The automatic fuel burner of claim 1 characterized by said free wheeling fan having an inertia element attached thereto whereby said fan shall be caused to continue its rotation after said fuel conveyor has stopped.

3. In a stoker, the combination of a fuel delivery conveyor for moving fuel into a combustion zone, a motor for driving said conveyor, an air delivery fan driven by said motor for supplying air to the combustion zone, a free wheeling clutch between said motor and said air delivery mechanism, and a fly wheel on said air delivery mechanism adapted to continue the rotation of said fan after the fuel delivery has ceased.

4. An automatic fuel burner comprising in combination a fuel feeding means, an air feeding means, said air feeding means including a rotary air impeller, a motor, said motor being operatively connected with said fuel feeding means to cause fuel to be fed to the combustion zone of said burner, and means operatively connecting said motor with said impeller to cause air to be fed to the combustion zone of said burner, said last mentioned means comprising an over-running clutch whereby said impeller may be positively driven by said motor in one direction of rotation only and whereby after said impeller has attained a certain speed in said one direction due to the driving action of said motor the motor speed may be reduced without thereby reducing the speed of said impeller in a proportional amount.

5. The automatic fuel burner of claim 1 characterized by having said impeller provided with an additional inertia element to store rotative energy while said impeller is being driven by said motor in said one direction and to give up said energy to said impeller to aid in maintaining the rotative speed of said impeller when the driving force of said motor on said impeller is reduced.

ERNEST C. WEBB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,039,099 Cook Sept. 24, 1912 1,455,910 Domarus May 22, 1923 1,970,383 Lauterbur Aug. 14, 1934 1,985,934 Logan Jan. 1, 1935 2,178,171 Hellman Oct. 31, 1939 2,277,630 Bressler Mar. 24, 1942 2,306,189 Schweickart Dec. 22, 1942 FOREIGN PATENTS Number Country Date 664,132 France Apr. 16, 1929 

